ECGenie Protocols

Below are simple protocols to follow that will broaden your understanding and skill in ECG monitoring. These easy-to-implement studies will bring about changes in ECG signal in your animals that are intuitive and translatable to human life. As such, as you pursue your own animal models and studies, the insights you glean from these exercises will greatly enhance your assimilation of ECG signals that you may see in your research. Please contact us any time to discuss your observations and data!

Title

Effects of Caffeine on Heart

Number of animals

3

Species/strain

Balb/c mice recommended

Instrumentation needed

ECGenie instrumentation

Reagents required

Mountain Dew Soda

Time to perform

15 minutes day 1 & 15 minutes day 2

Want access to the printable guide? Download the protocols by clicking Here

Heart rate measurement is routine in clinical establishments. The perception that monitoring the heart is difficult in small animals, however, makes ECG measurements in the laboratory the exception rather than the rule. The ECGenie, though, makes it incredibly simple to record the ECG in mice, rats, hamsters, and guinea pigs, from day 1 of life, through old age or death.

This provides tremendous opportunities for vital sign monitoring, general health monitoring, phenotyping, and discovery in animal models of human diseases. For example, mice with cardiac hypetrophy can be discerned by prolonged QRS interval durations. Mice in heart failure can be discerned by significantly reduced heart rate variability. The cardiotoxic effects of experimental therapeutics can include arrhythmia and prolonged QT interval duration. The ECGenie enables these non-invasive measurements to become routine in conscious lab animals.

As in humans, many factors can affect heart rate, heart rate variability, and the ECG interval durations [PR, QRS, QT, etc.] in small animals such as mice. Moreover, there are strain, gender, and age differences in the cardiovascular properties among mice. Here we present a very simple protocol to perturb the cardiovascular system by orally administered caffeine, and show the effects of ingestion of caffeine on the electrocardiogram.

This easy and fast protocol provides investigators an opportunity to learn 1st hand how even ingestion of a seemingly safe drug can have measurable effects on the cardiovascular system.

Caffeine has many effects, including central nervous system stimulation. Caffeine is believed to act as an adenosine receptor antagonist, increasing release of free fatty acids, and increasing calcium release and uptake. Consistent with what is known [and our own personal experiences no doubt], caffeine causes an increase in heart rate in mice. Since decreased heart rate variability (HRV) is a major risk factor for sudden death and cardiovascular disease, and caffeine consumption is quite popular, it is of interest to explore models and conditions in which subjects are more vulnerable to caffeine’s effects on HRV. In our hands, HRV was significantly reduced after 24 hour access to the caffeinated beverage.
The effects of caffeine our likely strain dependent. Of note, chronic [subcutaneous administration] of caffeine to pregnant dams (C57BL/6) led to activation of the renin-angiotensin system of the offspring, resulting in cardiac remodeling. These findings highlight the urge to encourage pregnant women to avoid caffeine. Via the LifeSpoon™ plug-in module for ECG recording in neonatal mice, it may be interesting to examine the effects of caffeine on the heart rate and heart rate variability of mice nursed by dams that consume caffeine.

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Tom Hampton – CEO & Founder, Mouse Specifics, Inc.

“It is clear that the mouse has become essential to our understanding of the mechanisms of numerous human diseases and development of therapies, and we are happy participants in this research. Yet, tens of millions of mice are sacrificed each year. With foresight and ingenuity, we should be able to efficiently obtain more and better data from every mouse.”